I think Phil Kessel is mis-labeled as a pure goal-scorer.
In his time in Toronto, he had the best shot and was their best player, so many players deferred to him, causing him to have to bear the goal-scoring load. He's not really a very versatile goal scorer though... Most of his goals on a far side snapshot (typically shooting at the left side of the net from the right wing). He went the entire 15-16 season with the Penguins without scoring a single slap-shot or true one-time goal.
In Pittsburgh, with more talented teammates he has emerged as a bit of a playmaker, and less of a one-trick goal scorer.
He was also labeled a locker room cancer in Toronto, and judging from the way the players and fans have received him here in Pittsburgh, this is clearly not the case.